Remove Sphinx as a required dependency (#18)

Signed-off-by: Ryan Northey <[email protected]>
Co-authored-by: Adam Turner <[email protected]>

Author: phlax

Diff for: .github/workflows/test.yml

@@ -44,7 +44,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          python -m pip install .[test]
+          python -m pip install .[test,standalone]
 
       - name: Test with pytest
         run: python -m pytest -vv --durations 25

Diff for: CHANGES

@@ -1,3 +1,10 @@
+Release 2.0.5 (unreleased)
+==========================
+
+* Remove Sphinx as a required dependency, as circular dependencies may cause
+  failure with package managers that expect a directed acyclic graph (DAG)
+  of dependencies.
+
 Release 2.0.4 (2023-08-14)
 ==========================
 

Diff for: pyproject.toml

@@ -39,9 +39,7 @@ classifiers = [
     "Topic :: Text Processing",
     "Topic :: Utilities",
 ]
-dependencies = [
-    "Sphinx>=5",
-]
+dependencies = []
 dynamic = ["version"]
 
 [project.optional-dependencies]
@@ -54,6 +52,9 @@ lint = [
     "mypy",
     "docutils-stubs",
 ]
+standalone = [
+    "Sphinx>=5",
+]
 
 [[project.authors]]
 name = "Georg Brandl"

Diff for: sphinxcontrib/htmlhelp/__init__.py

@@ -296,6 +296,7 @@ def default_htmlhelp_basename(config: Config) -> str:
 
 
 def setup(app: Sphinx) -> dict[str, Any]:
+    app.require_sphinx('5.0')
     app.setup_extension('sphinx.builders.html')
     app.add_builder(HTMLHelpBuilder)
     app.add_message_catalog(__name__, path.join(package_dir, 'locales'))